The disclosure generally relates to embedding particles into the polymer matrix of a medical device.
It is often desirable to embed or encapsulate nanometer-sized particles into the outer layer of medical devices. For example, super-paramagnetic particles can be placed within medical devices such as balloon catheters to thereby enhance the visibility of the device under magnetic resonance imaging (MRI). The super-paramagnetic particles disturb the local magnetic fields within the directly surrounding lumen in which the catheter is placed, and thereby become visible under MRI. Moreover, pharmaceuticals can be encapsulated within nanoparticles, which are then directed to a specific location within the body and released.
While it can therefore be seen that the incorporation of nanoparticles into medical devices has proven to be advantageous, current methods and apparatus for doing so are less than optimal. Currently, the dispersal of such nanoparticles through polymer matrices of medical devices is accomplished commonly through shear compounding. Such mechanical integration of the nanoparticles into the polymer matrix, however, typically is a relatively time-consuming, and thus costly process. Moreover, the forces involved negatively affect the quality of the polymer, and typically result in very poor dispersion of the particles throughout the device. In the event that pharmaceuticals are incorporated within the nanoparticles, such shear compounding also results in destruction of the pharmaceutical either due to the high resulting temperatures, or through the mechanical interaction.
It can therefore be seen that a need exists for an improved apparatus and method for incorporating nanoparticles into medical devices.
In accordance with one aspect of the disclosure, a method of embedding nanoparticles into a medical device is disclosed which comprises forming a solution containing the nanoparticles, spraying the solution from a charged nozzle, evaporating the solution to form a stream of charged nanoparticles, energizing an electrode to have a polarity opposite to the charged nanoparticles thereby generating a stream of charged nanoparticles, and placing a medical device into the stream. The charged nanoparticles are thereby embedded into the medical device upon impact.
In accordance with another aspect of the disclosure an apparatus for embedding nanoparticles into a medical device, is disclosed which comprises a housing, an electrostatic spray nozzle, and an electrode. The housing may include an inlet, an outlet linearly opposed to the inlet, a pressure chamber between the inlet and the outlet, and an off-axis vacuum chamber between the inlet and the outlet in fluid communication with the pressure chamber. The electrode may be placed within the vacuum chamber and be adapted to have a medical device mounted thereon.
In accordance with another aspect of the disclosure, a method of treating a medical device is disclosed which may comprise generating a stream of charged particles, mounting a medical device about and an electrode charged oppositely to the particles, and spraying the charged particles toward the medical device.
In accordance with yet another aspect of the disclosure, an apparatus for treating medical devices is disclosed which may comprise a source of charged particles, an electrode charged oppositely to the charged particles, a stream of charged particles extending from the source to the electrode, and means for mounting a medical device in the stream.
These and other aspects and features of the disclosure will become more apparent upon reading the following detailed description when taken into consideration with the accompanying drawings.